How to Use Synology Duplicate File Finder to Find Duplicate Files on Synology NAS

NAS (network-attached storage) is getting more and more popular these days. As with other types of data storage, such as your computer’s local storage, external storage and cloud storage, there can be duplicate files on your NAS drives. You may want to find and delete unwanted duplicates to free up space and better manage your files.

Synology is a well-known name in the world of NAS. In this article, I’m going to talk about how to use a Synology duplicate file finder to find and delete duplicate files on Synology drives.

How to use the native Synology duplicate file finder

Synology NAS itself actually provides a way to help users identify duplicate files. There are 4 facts about this native duplicate file finder for Synology NAS.

How to access it

You can make your Synology device more powerful by installing tools known as add-on packages. The Storage Analyzer package is one of them. With Storage Analyzer, you can perform various tasks, including identifying duplicate files on your Synology NAS.

How to find duplicates

According to Storage Analyzer, it can identify “potential duplicate files”. And there are 2 options to configure the identification: Ignore file names and Ignore modification time.

• With both “Ignore file names” and “Ignore modification time” being enabled, Storage Analyzer will identify duplicate files by only comparing files’ hash values. A hash value is a numeric value, which is unique to a file. If two or multiple files have the same hash value, then they are a set of duplicate files, regardless of how they are named.
• With only “Ignore file names” being enabled, Storage Analyzer will identify duplicate files by comparing files’ hash values and modification times.
• With only “Ignore modification time” being enabled, Storage Analyzer will identify duplicate files by comparing files’ hash values and names.

Note: By “potential”, Storage Analyzer means that it doesn’t compare full hash values, because comparing full hash values can take time. So, as you can see, Storage Analyzer seeks a balance between accuracy and speed. If you need a duplicate file finder that identifies duplicate files by comparing full hash values and provides high accuracy, you can go to this part of the article.

How many duplicates can be found

You can specify the maximum number of duplicate files to be found. For example, if there are 1000 duplicate files on your NAS and you set the max number to be 500, Storage Analyzer will stop finding once it has found 500 duplicates.

How to delete duplicates

In each set of duplicate files, you need to manually delete the redundant ones. It can take a while. If you are looking for a way to mass delete them, you can check out the third-party solution, which provides accuracy and efficiency.

Steps: Find duplicate files on Synology NAS with Storage Analyzer

1. In Synology DiskStation Manager, go to Package Center.

2. Search for Storage Analyzer, install it and open it.

3. Choose Create in the Report Profile section. Give the task a descriptive name, such as Duplicates. Click Next.

4. In the Select Report Items list, select the Potential Duplicate Files checkbox. Click Next.

5. Select in which folders you want to find duplicate files. Click Next.

6. Configure the identification of duplicate files based on your needs. Click Next.

7. In the Summary dialog, select the Generate reports now checkbox. Click Done.

Once the identification is done, go check out the report, and you will be presented with a list of duplicate files found on your Synology NAS. Go through each set of duplicate files and manually delete the redundant ones.

How to use the third-party Synology duplicate file finder

There are still other ways to remove duplicate files in Synology.

Available for Windows and Mac, Cisdem Duplicate Finder is an easy-to-use app to find and delete duplicate files. It can find duplicate photos, audios, videos, documents, archives and other types of duplicate files.

It identifies duplicate files by comparing both files’ full hash values (with the MD5 algorithm) and sizes, so as to provide the highest level of accuracy (by avoiding the probability of MD5 collision). Once finishing the identification, it will display all the duplicate files for you to preview and automatically select all but one file for deletion in each set of duplicate files.

Cisdem Duplicate Finder can help users find and delete duplicate files in different locations.

• You can use it to scan one or multiple folders on your Windows or Mac computer for duplicate files at a time. It can find duplicates in and across locations.
• You can use it to scan your external hard drive for duplicate files. To do so, you need to connect the external hard drive to your computer first so that it works just like a regular drive on your computer, which means you can directly create, edit and delete files on the external hard drive using your computer.
• You can also use it find duplicate files in Google Drive, OneDrive, Dropbox and more. To do so, you first need to set up your files to sync between cloud drive and your computer, which is very easy to do via your cloud drive’s desktop app. This way, your cloud drive can work like a regular drive on your computer. When you delete duplicate files in this drive on your computer, the deletion will automatically sync to the cloud, and vice versa.

In the same way, if you know how to successfully mount your Synology drive to your computer, you can use Cisdem Duplicate Finder as a duplicate file finder for Synology.

Important: If you are NAS-savvy and know exactly what you are doing, you can try this third-party solution. If the answer is no or you are not sure, then you may skip this solution.

Steps: How to find and delete duplicate files on Synology NAS with Cisdem Duplicate Finder

1. Mount your Synology NAS to your computer.

2. Download and install Cisdem Duplicate Finder.

Free Download   Free Download

3. Click the Add button + to select your NAS to scan. Click Scan.

4. When the scan is done, the results window will display duplicate files for you to view and preview.

5. In each set of duplicate files, all but one is automatically selected for removal. If you want, you can manually select/deselect. Or, you can choose a selection rule to apply the rule to the sets you highlighted in the left sidebar.

6. Once all the unwanted duplicates are selected for removal. Click Delete to get rid of them all at once.

Tip: Cisdem Duplicate Finder is an excellent duplicate photo finder, which can identify exactly identical photos, photos that look the same but different in resolutions, file sizes or formats, and similar photos in Synology NAS. If you only want to view the found exact duplicate photos, you can go to the Images tab of the results window. Non-exact duplicate photos and similar photos are listed under the Similar Images tab.

Conclusion

This article talks about two Synology duplicate file finders and how to use them respectively. One solution is from Synology itself, which is basic, not that customizable and requires you to delete duplicates by hand. The other one is third-party, which can provide more effectiveness and efficiency and requires you to be NAS-savvy. Which one is the best? I think it depends on your preferences.